Extending the Coordination Chemistry of Molecular P₄S₃:  The\nPolymeric Ag(P₄S₃)⁺ and Ag(P₄S₃)₂⁺ Cations

Abstract

Upon reacting P₄S₃ with AgAl(hfip)₄ and AgAl(pftb)₄ [hfip = OC(H)(CF₃)₂; pftb = OC(CF₃)₃], the\ncompounds Ag(P₄S₃)Al(hfip)₄ <b>1</b> and Ag(P₄S₃)₂⁺[Al(pftb)₄]^- <b>2</b> formed in CS₂ (<b>1</b>) or CS₂/CH₂Cl₂ (<b>2</b>) solution.\nCompounds <b>1</b> and <b>2</b> were characterized by single-crystal X-ray structure determinations, Raman and solution\nNMR spectroscopy, and elemental analyses. One-dimensional chains of [Ag(P₄S₃)<i>_x</i>]_∞ (<i>x</i> = 1, <b>1</b>; <i>x</i> = 2, <b>2</b>)\nformed in the solid state with P₄S₃ ligands that bridge through a 1,3-P,S, a 2,4-P,S, or a 3,4-P,P η¹\ncoordination to the silver ions. Compound <b>2</b> with the least basic anion contains the first homoleptic metal(P₄S₃) complex. Compounds <b>1</b> and <b>2</b> also include the long sought sulfur coordination of P₄S₃. Raman\nspectra of <b>1</b> and <b>2</b> were assigned on the basis of DFT calculations of related species. The influence of the\nsilver coordination on the geometry of the P₄S₃ cage is discussed, additionally aided by DFT calculations.\nConsequences for the frequently observed degradation of the cage are suggested. An experimental silver\nion affinity scale based on the solid-state structures of several weak Lewis acid base adducts of type\n(L)AgAl(hfip)₄ is given. The affinity of the ligand L to the silver ion increases according to P₄ < CH₂Cl₂ <\nP₄S₃ < S₈ < 1,2-C₂H₄Cl₂ < toluene.